‘I always do a lot of homework,” says Bill McGlaughlin, the folksy/erudite radio commentator and host of the syndicated classical music programs “Exploring Music” and “St. Paul Sunday,” syndicated on Mercer County College’s WWFM and across the country. “I use Grove’s 30-volume music encyclopedia. I have it online on my laptop. There are some composers I don’t know. I get to learn a lot.

“I always read through the music from the score. In my mind, I hear it come alive. I know how to spot what’s important. I read the score like a book and find the six-bar passage in the middle that embodies the essence of the piece.”

WWFM and McGlaughlin occupy a territory of mutual admiration. The proof? WWFM was one of the first to program McGlaughlin’s hour-long show “Exploring Music,” which debuted in 2003 and airs five times a week, focusing on one thematic topic each week. “That’s a lot of real estate,” says McGlaughlin in a telephone interview from his New York City home. “But they jumped in.”

A listener-supported entity founded in 1982, WWFM presents a distilled version of its operations in a benefit concert on Sunday, June 7, in Trenton War Memorial’s Patriots Theater. McGlaughlin serves as guest host for the event, which presents vocal, orchestral, and choral pieces showcasing performers based in the region. Among them are Julianne Baird, Palisades Virtuosi, Parthenia Viol Consort, Rutgers Collegium Musicum, Princeton Pro Musica, Lile Piano Trio, and Cordus Mundi.

“Peter Fretwell, [WWFM’s general manager] asked me out of the blue,” McGlaughlin says, “and I was pleased to be asked. WWFM has a special place in my affections. My mom, who lives in Abingdon, Pennsylvania, used to listen to WWFM programs, and used to write me long notes about them. I couldn’t get the station in New York, but I listened whenever I visited her.”

The concert will be recorded and become the fourth CD in WWFM’s series, “Celebrating our Musical Community.” Performers on the three previous discs make up a roster of well-known musicians in the area, including Philadelphia, and present music ranging from the 16th century to the present.

A 30-year veteran broadcaster for National Public Radio, McGlaughlin is also a composer and conductor. As a trombonist he has performed in major symphony orchestras. Despite his professional accomplishments, he has a keen understanding of what the curious, but untutored, listener needs to know for understanding music. Moreover, he is capable of captivating simultaneously both experienced musicians and newcomers.

“I’ll add insight,” McGlaughlin says about the War Memorial concert. “I’ll walk around with a microphone, insinuate myself into the alto section, and ask questions about what they justsang.

“I’ve done a lot of this kind of thing,” he continues. “As assistant conductor for the St. Paul Chamber Orchestra, I had to talk a lot from stage. St. Paul was always changing programs so they had to be announced at the concert. As assistant conductor, I conducted more than the famous main conductors who were often absent.

“The orchestra toured a lot in the upper Midwest, and I talked when they toured. In Bismarck, for instance, audiences were eager but not sophisticated so I wanted to give them a little hand on the music.” McGlaughlin does not specify whether he means Bismarck, North Dakota, or South Dakota.

“Music goes by so fast,” he says. “Performers get to know it because of repetition in rehearsals. For the audience, it comes flying by, with no chance to say ‘Can I hear that again?’ That’s why I play it again, often on piano, in my broadcasts. It’s great to help people catch on. There’s nothing more wonderful than learning.

“I don’t use a script,” McGlaughlin says. “A while ago I was interviewing Franco Gulli, a violinist at Indiana University, and he was worried. He asked, ‘Where’s my script?’ I’m still finishing my show and I reassured him. I told him he didn’t have to know any numbers, like when the composer was born. I take care of that and just get people I interview to talk the way musicians talk all the time.

I wonder aloud to McGlaughlin, what happens when the performers perceive the music differently from him? “It won’t matter if the choral director doesn’t think the way I do. I don’t play ‘gotcha.’ I love it when something happens that I didn’t think of, and it knocks me dead.”

Asked how he will prepare for the War Memorial concert, he says matter-of-factly, “I’ll iron my shirt. As a conductor, I use many shirts. I learned that it’s easier to iron your own shirt than go to the cleaners. Ironing your shirt is like warming up. It gets you in the mood.”

In our conversation McGlaughlin tosses off responses that ricochet away from a straight answer. “How did you get involved in the benefit concert?” I begin. “Did you select the program, or were you told, `Here’s our program. Make it coherent.’?”

“Not either one,” he answers. “It’s a rehabilitative project, sort of community service, part of the terms of my parole.” As I realize that his answer is off-the wall, he says, “This is goofy talk. It’s the first time I’ve ever done this goofy talk. But it’s a nice day, and a nice time of day, and I’m just sitting here drinking coffee.” To me he sounds playful and wound-up.

“I hope it’s decaf,” I venture. Decisively, he responds, “It’s not decaf. Decaf is a terrorist plot to prevent you from being vigilant.”

This, I think to myself, is just the kind of guy I want examining musty scores with his X-ray musical mind and telling me what he finds.

The eldest of six children, McGlaughlin was born in Philadelphia in 1943 while his draftsman father, a native of Merchantville, New Jersey, served in the Army Air Corps in India. “The first man I saw was my Scottish grandfather,” he says. “I’m a Philadelphia person. I studied at Temple.

“My pop taught me to play a scale on the harmonica when I was six,” he says. “When I asked him what to do next, he said, `You know a lot of songs. Just play them. So I did. Pop and I used to play opera — a lot of Verdi, and even Wagner — on harmonicas together. I learned an important lesson from that: Music is something you do by ear with somebody you love.

“I still play by ear,” McGlaughlin continues. “I have perfect pitch. It’s not a big deal. Perfect pitch does not equal being a great musician. It just means you have a well-developed memory of pitch.”

At age 14 McGlaughlin had his first piano lesson, when he took over the pre-paid lessons intended originally for his younger brother. “It was a late start for piano,” he says. “But I fell in love with it. At 14, I worked like a dog, playing piano eight hours a day.”

In high school, McGlaughlin started studying trombone, which he thinks of as his primary instrument. Immediately after earning a bachelor’s degree from Temple in 1967 he joined the Philadelphia orchestra. In 1969 he collected a master’s degree in conducting from Temple. He played trombone with the Pittsburgh Symphony Orchestra from 1969 to 1975. A conductor for the Minneapolis-St. Paul Chamber Orchestra from 1975 to 1982, he continued to play trombone with St. Paul.

“Trombone shaped my approach to music,” he says. “If you play in an orchestra like Philadelphia, you get access to great conductors and great performers. Playing trombone got me a front row seat inside the band. When you’re on stage you see how the conductor organizes a piece. I used to put an orchestral score on my stand to understand what the conductor was doing. In the Pittsburgh Orchestra the other trombonist would have to kick me when it was time to come in because I was so involved in what the conductor was trying to get the violas to do.

“Great conductors inspire you. You can’t imitate them. You would not want to. It would be like copying a passage out of someone’s journal into your journal. It wouldn’t work. You’ve got to do it yourself.

“Actually, maybe I learned more from watching conductors who were not very good than from watching great conductors. The most important thing I learned was how well you must know the score to do it well.”

McGlaughlin played trombone until he developed a massive conducting career. “Playing trombone is very physical,” he says. “You have to keep in shape.”

After St. Paul, he directed orchestras in Eugene, Oregon; Tucson, Arizona; San Francisco, California; and Kansas City, Missouri. In 1998, after 23 years as a conductor, McGlaughlin turned from conducting to composing, and moved to New York City, where he lives with his wife, jazz singer Karrin Allyson. He describes his composing style as “more intuitive than intellectual.”

For almost 30 years a constant in McGlaughlin’s life has been his career as a radio broadcaster. “St. Paul Sunday” debuted in 1980 on National Public Radio in Minneapolis and continues to attract listeners. “Exploring Music” is 23 years younger. Between them the shows air on hundreds of radio stations, stream on the Internet and can be heard via satellite stations.

“I’m not trained as a broadcaster,” McGlaughlin says. “But I have a unique voice and I’m a musician. Minneapolis NPR encouraged me to be myself.”